DESCRIPTION: This application for an Independent Scientist Award (ISA) is mad by Dr. Matthew W. Kelley, a newly appointed Assistant Professor in the Department of Cell Biology at Georgetown University. Dr. Kelley obtained his Ph.D. in the laboratory of Dr. Jeffrey Corwin at the University of Virginia. His graduate studies focused on the cellular and morphological development of the organ of Corti. For his post-doctoral training, Dr. Kelley received an NR entitled "Effects of Retinoic Acid During Retinal Development." Post-doctoral research was conducted in the laboratory of Dr. Thomas Reh at the University o Washington in Seattle where he received training in immunocytochemical and molecular biological techniques. He has had memberships in several profession societies such as ARO (pending), ARVO, AAAS, and the Society for Neuroscience. Dr. Kelley has published six research articles in peer-reviewed journals (including J. Neurosci.) and has one manuscript in preparation. Dr. Kelley's long-term goals are to understand how the different cell types within the organ of Corti are determined during development. Most immediately Dr. Kelley is interested in studying the factors that influence the determination and differentiation of hair cells. The research proposal outlin in this ISA uses molecular techniques learned during his post-doctoral trainin to test several hypotheses related to the determination of cells as hair cells Many of these hypotheses are based on the results of experiments Dr. Kelley conducted as a graduate student. Both the complexity of the development of th organ of Corti as well as the relatively small quantity of tissue available in the developing cochlea may require some time to determine which molecular techniques are more appropriate to address specific hypotheses. As a new Assistant Professor, this ISA will provide the time to build a strong and acti laboratory that can examine important clinical and basic science questions in cochlear development. Dr. Kelley plans to devote a minimum of 80% of his time engaged in laboratory research. The remaining time will be spent primarily on activities related to teaching and research training.